• Title/Summary/Keyword: surrounding plants

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Two Types of Forest Vegetation in Kyungpook Area

  • Ri, Chong Un
    • The Korean Journal of Ecology
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    • v.3 no.1_2
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    • pp.17-20
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    • 1980
  • This paper contains the results obtained by ecological investigation of ilora in Muie Island of Incheon Harbor in the xestern coast in Korea. 14 varieties, 1-27 species, 57 families and 142 genera of Tracheophyta were recorded by field investigations conducted over three times in May and July, 1976 and August, 1980. The flora of this island showed a plant community predominated by Pinus densiflol-a grown in miggle with Carpinus laxiflora, Quel-cus serrata and Rhododendron muucronulatum. Generally, the number of plant species was scarce, but it was an unexpected result that such remote mountainous plants as Lysinzachia clethrozdes, Sy7zeilesis palnzata and Lilzunz disttcum etc. were encountered in a wood surrounding Seohwang-dang, the shrine of a tutelary deity, on 126-Meter Hill at the northern end of the island. There also countered in Hoyong mountain valley were deciduous broad-leaved forests without pine tree which mainly consisted of Prunus leveillea7za, Fraxinus rhynchophylla, Platycarya strofilada, Quercus serrata. Quercus acutissznza and Acer mono. In addition, herbaceous plants, such as Syneilesis palmata, Codonopsis lanceolata and Lysi\ulcornerna barystnchy were grown as the undergrowth of these forests. Drosera rotundifolio, an unlooked-for plant, . appeared in the middle of the eastern coast of the island. Camellia japo7tica was grown spontaneously in Deogjeog Island 261cm southwest from the island, while no evergreen broa-leaved tree could be located except 2 species of Vztex rotztndifolia and Euo~zymus japonrca. It may be considered that such simple flora of this island compared with that of land is attributed to the fact that the formation of the former took place in the period far latter than that of the latter.

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A Study for Flaw Detection of 3/4″ Pipe by Using Guided Wave (유도초음파를 이용한 3/4″ 배관 결함 검출 연구)

  • Chung, Woo Geun;Kim, Jin-Hoi;Cheon, Keun Young
    • Transactions of the Korean Society of Pressure Vessels and Piping
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    • v.15 no.1
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    • pp.40-45
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    • 2019
  • Unlike the welded pipes in the primary system of light water nuclear power plants being periodically inspected with in-Service inspection program, relatively small pipes with the outer diameter less than 2 inch have not been regularly inspected to date. However, after several failure reports on the occurrence of critical crack-like defects in small pipes, inspection for the small pipes has been more demanded because it could cause the provisional outage of nuclear power plants. Nevertheless, there's no particular method to examine the small pipes having access limitations for inspection due to various reasons; inaccessible area, excessive radiation exposure, hazardous surrounding, and etc. This study is to develop a reliable inspection technique using torsional and flexural modes of guided wave to detect defects that could occur in inaccessible area. The attribute of guided wave that can travel a long distance enables to inspect even isolated range of the pipe from accessible location. This paper presents a case study of the evaluation test on 3/4" small-bore pipes with guide wave method. The test result demonstrates the crack signal behavior and assures possibility to detect the crack signal in a flexural mode, which is clearly distinguishable from the symmetric structure signal in a torsional mode.

Consistency issues in quantitative safety goals of nuclear power plants in Korea

  • Kim, Ji Suk;Kim, Man Cheol
    • Nuclear Engineering and Technology
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    • v.51 no.7
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    • pp.1758-1764
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    • 2019
  • As the safety level of nuclear power plants (NPPs) relates to the safety of individuals, society, and the environment, it is important to establish NPP safety goals. In Korea, two quantitative health objectives and one large release frequency (LRF) criterion were formally set as quantitative safety goals for NPPs by the Nuclear Safety and Security Commission in 2016. The risks of prompt and cancer fatalities from NPPs should be less than 0.1% of the overall risk, and the frequency of nuclear accidents releasing more than 100 TBq of Cs-137 should not exceed 1E-06 per reactor year. This paper reviews the hierarchical structure of safety goals in Korea, its relationship with those of other countries, and the relationships among safety goals and subsidiary criteria like core damage frequency and large early release frequency. By analyzing the effect of the release of 100 TBq of Cs-137 via consequence analysis codes in eight different accident scenarios, it was shown that meeting the LRF criterion results in negligible prompt fatalities in the surrounding area. Hence, the LRF criterion dominates the safety goals for Korean NPPs. Safety goals must be consistent with national policy, international standards, and the goals of other counties.

A study on the development of drainage system for rapid drainage of thermal power plant outdoor coal storage during rainfall and characteristics of discharged water quality (강우시 화력발전소 옥외저탄장 신속한 배수를 위한 배수시스템 개발 및 배출 수질 특성에 관한 연구)

  • Lim, Chang-Min;Kwon, Hyun-Woo;Kim, Young-Min;Cho, Do-Young;Lee, Gun-Cheol
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2022.11a
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    • pp.189-190
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    • 2022
  • Power plants that produce electricity through thermal power plants mainly store coal in outdoor storage yards. In particular, coal is directly exposed to rainwater during rainfall, including torrential rain. There is no separate drainage facility in the outdoor coal yard, and coal is simply stored on the ground. Accordingly, during rainfall, coal dust flows down by rainwater, and a large amount of rainwater that is not drained overflows the outdoor coal yard, overflowing the surrounding facilities and causing environmental pollution. Therefore, in this study, a drainage system was developed for the rapid drainage of an outdoor coal mine, and the quality of the water was evaluated when rainwater mixed with drainage characteristics and coal dust was discharged through the drainage system.

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Understory Species Composition and Pinus densiflora Natural Regeneration in Pinus densiflora Stands Regenerated by Seed-Tree Method (소나무 모수림 시업지의 하층식생 종 조성과 소나무 천연갱신양상)

  • Byeon, Seong Yeob;Yun, Chung Weon
    • Journal of Korean Society of Forest Science
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    • v.107 no.1
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    • pp.25-34
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    • 2018
  • This study was performed to discover the comparison of the understory species composition and the growth velocity of the regeneration seedlings in Pinus densiflora forests being managed by the seed-tree method from 2008 year. The investigation site located in Bonghwa, Gyeongsangbuk-do province was established by eighteen quadrats such as six control ones, six slope ones and 6 concave ones, in which we carried out the vegetation survey and measured annual height growth of each seedlings. As a result of vegetation analysis, the understory vegetation of the seed-tree forest area was mainly composed of shrub plants such as Lespedeza bicolor, Zanthoxylum schinifolium, Securinega suffruticosa, Lespedeza maximowiczii and Stephanandra incisa, herb plants such as Miscanthus sinensis var. purpurascens, Carex humilis var. nana, Spodiopogon sibiricus and Artemisia keiskeana, and vine plants such as Pueraria lobata, Smilax sieboldii, Dioscorea batatas, Actinidia arguta, Vitis amurensis and Rubus crataegifolius. Especially, the vine plants were relatively more imported to the concave site than the control site and the slope site. As a result of measurement of growth velocity, the seedlings of the Pinus densiflora appeared to be 3,175 trees/ha for the non-suppressed trees and 7,842 trees/ha for the suppressed trees. In cases of the concave site, individuals of seedlings were much lower than those on the slope site, probably due to the competition effects of vine plants. Consideringly, silvicultural practices for clearing the vine plants should be inevitably accompanied. Also, the growth velocity of the suppressed and non-suppressed trees has been constantly increasing, those of the non-suppressed trees much higher than the suppressed trees. This represents that the seedlings grow rapidly after the suppressed period with competition to the surrounding plants. Therefore, specific practices such as blush control and vine clear should be carried out at the beginning stage of regeneration in the seed-tree stand.

Distribution Characteristics of Alien Plants by Wetland Types in the Ecologically Outstanding Wetlands of South Korea (국내 생태우수습지의 유형별 외래식물상 현황 및 특성)

  • Chu, Yeounsu;Cho, Kwang-Jin;Kim, Mijeong;Lee, Changsu;Yoon, Jungdo;Lim, Jeoncheol
    • Ecology and Resilient Infrastructure
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    • v.7 no.3
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    • pp.145-159
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    • 2020
  • Wetlands are vulnerable to biological invasion by alien species, because they function as sinks that accumulate excess water, sediments, nutrients, and other contaminants from the surrounding watersheds by disturbance. In this study, to understand the status and characteristics of the alien plants based on the type of wetlands, we classified 24 ecologically outstanding wetlands and analyzed the status of alien flora. A total of 130 alien plants were found in the wetlands, accounting for 11% of the total plant species. Among them, the Asteraceae species was the most diverse, with 40 species. Erigeron annuus and Oenothera ordorata had the highest frequency of occurrence. The species richness of alien plants in the riverine and lacustrine wetlands (average: 30 species) was higher than that in the mountainous palustrine wetlands (average: 10 species). The same results were found in the naturalization index, urbanization index, and ratio of annuals and biennials, which indicate the degree of artificial interference. In the cluster analysis, the riverine and lacustrine wetlands were combined, and only the mountainous palustrine wetlands were separated. The number of alien plants is remarkably low in the mountainous palustrine wetlands, and it is considered to be the influence of Erigeron strigosus, Symphytum officinale, and Bilderdykia convolvulus, not found in the other types of wetlands. In particular, invasive alien plants such as Aster pilosus, Ambrosia trifida, Sicyos angulatus, Ambrosia artemisiifolia var. elatior were found intensively in the riverine wetlands. Therefore, it is considered that a methodical management is urgently required considering the dispersal of alien plants in the riverine and lacustrine wetlands with high artificial interference.

Plant Species Utilization and Care Patterns Using Potted Plants in the Traditional Gardening (전통조경에서 분(盆)을 이용한 식물의 활용과 애호 행태)

  • Kim, Myung-Hee
    • Journal of the Korean Institute of Traditional Landscape Architecture
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    • v.31 no.3
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    • pp.61-74
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    • 2013
  • This study examined and analyzed ancient writing and poetry regarding cases of appreciating plants by using pots in a garden of a palace or private houses by ancestors, and examined shape and planting method of plant species and potted plants, arrangement and preference of potted plants. As for the method of the study, description research method which examines and interprets poem and painting based on potted plants. The results of this study is summarized like the following. First, the plants which were favorably used for potted plants include 19 kinds such as Prunus mume, Pinus densiflora, Pinus pumila, Phyllostachys spp., Camellia japonica, Punica granatum, and Gardenia jasminoidesa, and as for herbs, 12 kinds such as Chrysanthemum monifolium and Nelumbo nusifera . Second, the species which were specially arranged into artificial shapes include Prunus mume and Pinus densiflora. The two plants made the shape of severe curves of stems such as Wangpi. Gyuban, and Bangan, and there are Pinus densiflora dwarfed potted plant whose roots are stretched on Prunus mume grafted into a strange stump and an oddly shaped stone. For the beauty of the dwarfed tree shape, pine cones are added to an old Pinus densiflora or Parthenocissus tricuspidata is planted to stems, and additional method of making moss on the soil, which is called 'Jongbunchuigyeong'. As for planting method, water culture, planting on a stone, planting on a charcoal, and assembled planting are expressed in poetry. Third, as for external space for potted plants, a place where a king stays, a bed room for a king, surrounding areas and gardens of private houses, and step stones were used as a space which adds artistic effects. Potted plants are placed on a table in a library, on a desk, on a drawer, and near a pillow as a small items in a room, and scholars enjoyed original characteristics and symbolism of the potted plants. Fourth, at the time of flowering of Prunus mume, poetry event was held to enjoy the tree and writing poetry begun. And at the time of flowering of Chrysanthemum monifolium, the flowers were floated in a liquor glass or shadow play was enjoyed. Fifth, potted plants played the role of garden ornaments in elegant events of a palace, the gentry, wedding ceremony, and sacrificial rites. Sixth, potted plants were used as tributes between countries, donation to a king, or a gift of a king. In addition, there were many cases where scholars exchanged potted plants and there is the first record of giving a potted plant in 'Mokeunsigo' by Mokeun Isaek, scholar in the late era of Goryeo. Seventh, at the time of flowering Prunus mume, Chrysanthemum monifolium, Gardenia jasminoides, Nelumbo nusifera, and Narcissustazetta var. chinensis, they enjoyed the particular fragrance and express it into poetry. Eighth, plant species from southern parts such as Camellia japonica, Daphne odora, Gardenia jasminoides, Citrus unshiu, Phyllostachys spp., Punica granatum, Rosa rugosa, and Musa basjoo, or foreign plant species, and species weak against the cold were utilized as pot plants for enjoying green trees indoors in northern central province in harshly cold winter.

Distribution Characteristics of Riparian Vegetation in the Mid and Lower Reaches of the Nakdong River, Korea (낙동강 중.하류지역의 수변 식생 분포 특성)

  • Yeo, Un-Sang;Lee, Yong-Min;Kim, Ki-Sup;Sung, Ki-June;Kang, Dae-Seok;Lee, Suk-Mo
    • Journal of Environmental Science International
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    • v.17 no.2
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    • pp.149-162
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    • 2008
  • Aquatic and riparian vegetation of river ecosystems are very important both in ecological and management perspectives. Vegetation surveys were conducted to understand the characteristics of riparian vegetation in the mid and lower reaches of the Nakdong River, Korea. A total of 68 families and 260 species were identified at eleven survey sites. The numbers of taxa were similar to those reported in a previous survey in 1996,but the percentage of naturalized plants increased more than two times compared to that in the previous survey. Survey sites near Yangsan Bridge and Nambu Park in Yangsan showed the highest percentage of naturalized plant species. Urbanization indices of the survey sites were high at 18.8% on average. Therophytes were the most dominant plant life form at the survey sites with 39.2% of total plants identified, followed by phanerophytes (19.2%), hemicryptophytes (18.9%), aquatic plants (13.9%), cryptophytes (5.8%), and chamaephytes (3.1%). The relative composition of hemicryptophytes decreased whereas those of therophytes and chamaephytes increased compared to those in the survey in 1996. This may be due to increase in dryness of riparian soils or degradation of riparian areas. Plant compositions at sites near Jeokpo Bridge and Hwoicheon suggest that the composition and distribution of riparian vegetation are affected by land use pattern surrounding riparian areas or human accessibility to the areas.

Defining Area of Damage of 2012 Hydrofluoric Acid Spill Accident in Gumi, Korea (구미 불산 누출사고로 인한 주변지역 환경영향권 설정에 관한 연구)

  • Koh, Dohyun;Kim, Jeongsoo;Choi, Kyungho
    • Journal of Environmental Health Sciences
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    • v.40 no.1
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    • pp.27-37
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    • 2014
  • Objectives: On September 27, 2012, leakage of anhydrous hydrofluoric acid occurred in a chemical plant in the Gumi National Industrial Complex. Following the accident, local factory workers and residents complained of abnormal health conditions. In addition, visual discolorations were widely observed in crops and trees in surrounding areas. The main objectives of the present study were to identify the area that was affected by the spill using data obtained from plants, soil, and water samples after the accident. Methods: Fluoride concentrations were analyzed in pine tree needles, soil, nearby streams, ponds and reservoirs collected from an area within a radius of three kilometers from the plant where the leak occurred. Fluoride concentrations in the air at the time of leakage were then estimated from fluoride concentrations that were measured in the pine tree needles. A Kriged map was developed to describe the spatial distribution of hydrofluoric acid at the time of the leakage and was compared with the area designated as a Special Disaster Zone by the government. Results: The Special Disaster Zone did not include all the affected area that was estimated by the Kriged map. Analytical results of the environmental samples also supported this discrepancy. Conclusion: Using plants, atmospheric concentrations of fluoride at the time of the leakage could be estimated. For the area that was identified as affected, further public health risk assessment and environmental risk assessment should be considered. Also, in the absence of air monitoring at the time of leakage, studies employing plants may be conducted in order to better understand the spatial extent and severity of the contamination.

Review of Unplanned Release at Foreign Nuclear Power Plants and Radiological Monitoring at Korean Power Plants (해외원전 비계획적 방출 및 한국의 환경감시 현황 분석)

  • Park, Soo-Chan;Ham, Baknoon;Kwon, Jang-Soon;Cho, Dong-Keun;Jeong, Jihye;Kwon, Man Jae
    • Journal of Soil and Groundwater Environment
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    • v.23 no.4
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    • pp.1-15
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    • 2018
  • Despite of safety issues related to radiological hazards, 31 countries around the world are operating more than 450 nuclear power plants (NPPs). To operate NPPs safely, safety regulations from radiation protection organizations were developed and adopted in many countries. However, many cases of radionuclide releases at foreign NPPs have been reported. Almost all commercial NPPs routinely release radioactive materials to the surrounding environments as liquid and gas phases under control. These releases are called 'planned releases' which are planned, regularly monitored, and well documented. Meanwhile, the releases focused in this review, called 'unplanned releases', are neither planned nor monitored by regulatory and/or protection organizations. NPPs are generally composed of various structures, systems and components (SSCs) for safety. Among them, the SSCs near reactors are closely related to safety of NPPs, and typically fabricated to comply with stringent requirements. However, some non-safety related SSCs such as underground pipes may be constructed only according to commercial standards, causing the leakage of radioactive fluids usually containing tritium ($^3H$). This paper discusses SSCs of NPPs and introduces several cases of unplanned releases at foreign NPPs. The current regulation on the environmental radiological surveillance and assessment around the NPPs in South Korea are also examined.